Plug connection for optical waveguides

ABSTRACT

The invention relates to a plug connector for an optical waveguide ( 5 ), which has a sheathed, light-conducting core ( 1 ) and an outer cladding ( 3 ) which surrounds the core sheathing ( 2 ), having a plug part ( 6 ), which can be plugged together with a mating plug part ( 7 ), the plug part ( 6 ) forming a tube ( 8 ) for insertion of the core ( 1 ), which can be severed flush with the tube end ( 9 ), and the mating plug part ( 7 ) forming a shaft ( 10 ) for insertion of the tube ( 8 ), which shaft ( 10 ) at the foot side is directed toward a transmitting/receiving element ( 11 ). It is of relevance that the plug part ( 6 ) is of two-part configuration, having a retaining part ( 12 ), which includes the tube ( 8 ) and holding means ( 13, 14 ) for the core sheathing ( 2 ) and also the outer cladding ( 3 ), and a cap part ( 15 ), which can be clipped in a watertight manner to the retaining part ( 12 ) and has a passage opening for the optical waveguide ( 5 ).

[0001] The invention relates to a plug connector for an opticalwaveguide, which has a sheathed, light-conducting core and an outercladding which surrounds the core sheathing, having a plug part, whichcan be plugged together with a mating plug part, the plug part forming atube for insertion of the core, which can be severed flush with the tubeend, and the mating plug part forming a shaft for insertion of the tube,which shaft at the foot side is directed toward a transmitting/receivingelement.

[0002] A plug connector of this type forms part of the prior art.However, the known plug connector is not waterproof. To make a plugconnector of this type watertight, DE 100 09 845, which is not a priorpublication, proposes fitting an O-ring seal inside the plug part, whichis to fit in a sealing manner around the core sheathing.

[0003] The invention is based on the object of making the plug connectorwhich is known from the prior art watertight.

[0004] The object is achieved by the invention described in the claims.

[0005] claim 1 provides first of all and in particular that the plugpart is of two-part configuration, having a retaining part, whichincludes the tube and holding means for the core sheathing and also theouter cladding, and a cap part, which can be connected in a watertightmanner to the retaining part and has a passage opening for the opticalwaveguide. This configuration results in a plug part which is easy toproduce and simple to connect to the optical waveguide. In a preferredrefinement of the invention, it is provided that the holding means arethreaded sections for the core sheathing and the outer cladding to bescrewed into. To secure the optical waveguide to the plug part, it isnecessary to uncover the optical waveguide or the core sheathing incertain regions. Then, after the cap part has been pushed over theoptical waveguide, that section of the optical waveguide from which theinsulation has been removed in this manner is plugged into the rearopening in the plug part until the end edge of the core sheathing or theend edge of the outer cladding comes into contact with the threadedsection. Relative rotation of the plug part with respect to the opticalwaveguide then causes those sections of core sheathing and of the outercladding from which the insulation has been removed to be screwed intothe associated internal screw thread of the plug part. In a preferredconfiguration, although the threaded sections inside the cavity of theplug part have different diameters, they have the same thread pitch. Theresult of this is that the core sheathing and the outer cladding can bescrewed simultaneously into the associated screw threads. The threadedsection which holds the core sheathing can be seated directly to therear of the tube. In a preferred refinement, it is provided that the atleast one section of the threaded section which holds the core sheathingis associated with a flange having a funnel-shaped opening. This flangeprojects above the base of the cavity which is associated with thethreaded section holding the outer cladding. This cavity has a rear end,into which the optical waveguide can be slugged and which is in the formof an inner-cone section. The cap part which closes off this opening canbe clipped to the retaining part. The tube into which the opticalwaveguide is plugged is surrounded by a tube projection which has anoutwardly facing annular bead. This tube projection is plugged into anannular slot in the mating plug part. The annular slot surrounds a corewhich is formed by a pedestal which forms the shaft into which the tubeis plugged. The radially outer boundary of this annular slot is formedby a snap-action rim which engages over the bead in a watertight manner.The snap-action rim itself is formed by a soft plastic sleeve which isintegrated in a watertight manner in the mating plug part.

[0006] The invention also relates to the plug part of the plugconnector.

[0007] An exemplary embodiment of the invention is explained below withreference to appended drawings.

[0008] The left-hand part of FIG. 1 shows the plug part which has beenplugged into the mating plug part, with the mating plug part illustratedin section, while the right-hand part of FIG. 1. shows the plug partplugged into the mating plug part, with the plug part illustrated insection.

[0009] The optical waveguide 5 has a core 1 which is made from amaterial which conducts light waves. The core 1 is surrounded by a coresheathing 2. This core sheathing 2 may consist of plastics. The coresheathing 2 is surrounded by tension-relieving fibers 4. The outercladding 3 surrounds the latter.

[0010] The plug part 6 is of two-part form. It comprises only aretaining part 12 and a cap part 15 which closes off the rear opening ofthe retaining part 12. Cap part 15 and retaining part 12 are formed asinjection moldings.

[0011] On the plug-in side, the retaining part 12 has a tube 8 in whichthe core 1 lies, so that its end projects beyond the tube end 9. It canthen be cut off flush with the tube end 9. The tube 8, which comes outof the front end face of the retaining part 12, is coaxially surroundedby a tube projection 24. This tube projection 24, which is joinedintegrally in terms of materials to the tube 8, has an outwardlyprojecting bead 22.

[0012] At its end, the tube 8 widens toward the plug interior to form aninternal screw thread 14, into which the core sheathing 2 can bescrewed. The internal screw thread 14 is in certain regions associatedwith a flange 16 which originates from the base of the inner cavity ofthe retaining part 12. To facilitate introduction of the core sheathing2 into the screw thread 14, the threaded section 14 opens out in theshape of a funnel 17.

[0013] The cavity has a second screw thread 13 of larger diameter. Thisthreaded section 13 is used for the outer cladding 3, around which thetension-relief fibers have been laid toward the rear, to be screwed intoit.

[0014] To make it easier to introduce the outer cladding 3, the openingof the cavity 18 has a conical rim section 19. In the region of theconical rim section 19, the retaining part 12 forms an annular beadwhich projects radially outward and over which a snap-action rim of thecap part 15 can be clipped. The cap part 15 has inner sealing lips 12,which bear in a sealing manner against the outer cladding 3.

[0015] The cap part 5 closes off the cavity 18 in a watertight manner.

[0016] The tube 8 is plugged into the shaft 10 of a pedestal 23 of themating plug part 7. The tube end 9 in the process comes to bear incontact or almost in contact with a transmitting/receiving element 11which is associated with the base of the shaft 10. When the plug part 6is plugged into the mating plug part 7, the tube projection 24 passesinto the annular slot between pedestal 23 and snap-action rim 21, sothat the snap-action rim 21 can engage over the radially outwardlyprojecting bead 22 of the tube projection 24 in a watertight manner.

[0017] The plug part 6 is assembled as a result of, first of all, thecap part 15 being pushed over the outer cladding 3. Then, the core 1 andthe core sheathing 2 are uncovered in steps. The tension relief fibers 4are placed over the outer cladding 3 toward the rear. Then, that end ofthe optical waveguide from which the insulation has been removed isplugged into the cavity 18. In the process, the core 1 slides into thetube 8. Relative rotation of the plug part 6 with respect to the opticalwaveguide 5 causes the core sheathing 2 to be screwed into the internalscrew thread 14 and, at the same time, causes the outer cladding 3 to bescrewed into the internally threaded section 13 until the end of thecore 1 projects beyond the tube end 9. Then, the cap part is pushed overthe bead of the retaining part 15, and the projecting end of the core 1is cut off flush with the tube end 9.

[0018] All features disclosed are (inherently) pertinent to theinvention. The disclosure content of the associated/appended prioritydocuments (copy of the prior application) is hereby incorporated in itsentirety in the disclosure of the application, partly for the purpose ofincorporating features of these documents in claims of the presentapplication.

1. A plug connector for an optical waveguide (5), which has a sheathed,light-conducting core (1) and an outer cladding (3) which surrounds thecore sheathing (2), having a plug part (6), which can be pluggedtogether with a mating plug part (7), the plug part (6) forming a tube(8) for insertion of the core (1), which can be severed flush with thetube end (9), and the mating plug part (7) forming a shaft (10) forinsertion of the tube (8), which shaft (10) at the foot side is directedtoward a transmitting/receiving element (11), characterized in that theplug part (6) is of two-part configuration, having a retaining part(12), which includes the tube (8) and holding means (13, 14) for thecore sheathing (2) and also the outer cladding (3), and a cap part (15),which can be clipped in a watertight manner to the retaining part (12)and has a passage opening for the optical waveguide (5).
 2. The plugconnector according to claim 1 or in particular according thereto,characterized in that the holding means (13, 14) are threaded sectionsfor the core sheathing (2) and the outer cladding (23) to be screwedinto.
 3. The plug connector according to one or more of the precedingclaims or in particular according thereto, characterized in that asealing lip, which bears in a watertight manner against the outercladding (3), is associated with the passage opening in the cap part(5).
 4. The plug connector according to one or more of the precedingclaims or in particular according thereto, characterized in that thethreaded sections (13, 14) have different diameters but the same threadpitch.
 5. The plug connector according to one or more of the precedingclaims or in particular according thereto, characterized in that thethreaded section (14) which holds the core sheathing (2) is locatedimmediately to the rear of the tube (8).
 6. The plug connector accordingto one or more of the preceding claims or in particular accordingthereto, characterized in that at least one section of the threadedsection (14) which holds the core sheathing (2) is associated with aflange (16) with a funnel-shaped opening, which flange projects abovethe base of the cavity (18) associated with the threaded section (13)which holds the outer cladding (2).
 7. The plug connector according toone or more of the preceding claims or in particular according thereto,characterized by an inner-cone section (19) which is associated with theopening of the cavity (18).
 8. The plug connector according to one ormore of the preceding claims or in particular according thereto,characterized in that the cap part (15) is clipped to the retaining part(12).
 9. The plug connector according to one or more of the precedingclaims or in particular according thereto, characterized in thatretaining part (12) and cap part (15) are each plastic injectionmoldings.
 10. Plug (6) or a plug connection for an optical waveguide,which includes a sheathed, light-conducting core (1) and an outercladding (3) which surrounds the core sheathing, the plug part (6)forming a tube (8) for insertion of the core (1), which can be severedflush with the tube end (9), characterized in that the plug part (6) isof two-part configuration, having a retaining part (12), which includesthe tube (8) and holding means (13, 14) for the core sheathing (2) andalso the outer cladding (3), and a cap part (15), which can be connectedin a watertight manner to the retaining part and has a passage openingfor the optical waveguide (5), in particular having the features of oneor more of the preceding claims.